Metal mold for casting steel wheels



3 Sheets-Sheet 1.

(No Model.)

I W. SELLERS. METAL MOLD FOR CASTING STEEL WHEELS. No. 319,515.

Patented June 9, 1885.

J/z Caz eeZ.

Inventar.

N. PETERS, Phmxrulhcgmphur. Washinglnn, m;

(No Model.) 3 Sheets-Sheet 2. W. SELLERS. METAL MOLD FOR CASTING STEELWHEELS.

Patented June 9, 1885.

Invento'r Wit es e oumg zmiw.

l ||J.:\ll.

3 SheetsSheet 3.

Patented June 9, 1885.

W. SELLERS.

METAL MOLD FOR CASTING STEEL WHEELS. No. 319,515;

(No Model.)

I Inv nt 01'. fifl/m 5 :3

N. PETERS. mmum m mr. wumn m n. cy

fitnesses WILLIAM SELLERS, OF PHILADELPHIA, PENNSYLVANIA.

METAL MOLD FOR CASTING STEEL WHEELS.

SPECIFICATION forming part of Letters Patent No. 319,515, dated June 9.1885.

Application filed June 8, 1883. (No model.)

To aZZ whom it may concern.-

Be it known that I, WILLIAM SELLERS, of

the city and county of Philadelphia, in the State of Pennsylvania, haveinvented certain new and useful Improvementsin Metal Molds for CastingSteel Wheels; and I do hereby declare that the following is a full,clear, and exact description of my invention, which will enable othersskilled in said art to make and use the same.

My improvements are adapted to the casting of all forms of wheels inwhich the rim is connected with the hub by arms or by a plate or webthat is narrower than the rim; but as, perhaps, their most importantapplication, I will describe them with reference to the manufacture ofwheels for railways.

It is well known that the requirements of railway service demand a wheelwith solid hub, arms, and rim, or with a continuous web or plateconnecting the hub with the rim, and such'wheels have heretofore beenmade almost exclusively of cast-iron with a chilled tread. The higherspeeds and heavier traffic of the present railway system exactrequirements beyond the capabilities of cast-iron, and to meet also toimpart sufficient rigidity to the mold.

to retain the fluid metal in the proper shape until by cooling thisshape becomes fixed. The thickness and backing for the mold must be suchthat the pressure from the shrinkage of the cooling metal would crushthe mold before it would distort the wheel; but it must be sufficientlystiff to retain the metal in the proper shape until so far cooled as tobe per-- manent. The material of these molds is too porous to admit ofpouring the molten metal directly upon the surface, so that it isrequisite to wash the interior with plumbago or other refractorymaterial to impart asmooth surface to the mold, so as'to produce asimilar surface upon the casting, and as the earthy material of whichthe mold is composed, as well as the and gas when the molten metal camein contact with it, ample provision had to be made for the escape ofthese, as well as of the air contained in the mold. mold must berenewed, so that the operation is not only expensive, but tedious, andconsequently it has been found impossible to make such wheels at a pricethat would compete with steel-tired wheels having built-up centers ofother material.

In the development of the art of steel-casting it has been found thatthis metal, with a proper chemical composition, can. be cast perfectlysolid, having a density, ultimate strength, and ductility almostidentical with those of a steel-forgin g, and that these characteristics can be more certainly attained when the casting is made in ametal mold. As the shrinkage of caststeel is more than double that ofcast-iron, and as the fluid or semi-fluid steel has very littletenacity, a slight resistance from the mold would result in a rupture ofthe casting.

It is the object of my invention toobtain a metal mold which can beseparated to permit a, shrinkage of the cast metal, and which whenseparated will evenly support the casting; and to this end my inventionconsists in a metal mold provided with a rim, a supporting-frame bywhich a hub portion of the mold is supported, and a movablerelieving-annulus between the rim and the hub portion; and itfurther'consists in a metal mold provided with a rim andsupportingframes, which maintain the hub portions of the mold at theproper distance from each other, and provided, further, with a movableannulus, which determines the position of its hub portion radially; andit further consists in a metal mold provided with supportingframes, arim interposed between said supporting-frames, an-upper movable annulus,and a lower movable annulus, and devices for moving the upper and thelower annulus toward and from each other simultaneously; and it furtherconsists in a metal mold provided with an upper and a lower movableannulus and devices through which one annulus is made to counterbalancethe other; and it fur- For every casting this L wash upon its surface,would give off steam ther consists in a metal mold provided-with a spaceor spaces within the rim portion of the mold and above the true rim ofthe wheel to be cast therein, which space receives the cast metal tosupply the shrinkage in the rim of the casting as its cools. 1 It is tobe understood that by a solid hub I mean a hub not split or dividedradially or otherwise, as I contemplate either casting the i hub solidand boring it, or casting it with a central core and then boring it.

In order that my said improvements may be more fully understood, I willnow describe the construction of my mold and the manner of operating thesame, reference being had to the 1 accompanying drawings, which form apart of this specification, and in which Figure 1 is the plan of arailway-car wheel. having a solid hub and a continuousstraighti web orplate connecting the hub with the tread. Fig. 2 is a sectionalelevationof the mold-- frame and mold in which such wheel is cast, andshowing also asectionof the finished wheel l in position therein. Fig. 3is a plan of the mold-frame and mold. Fig. 4 is a sectional elevation ofthe same, showing the matrix in which the metal is cast. Fig. :5 is aside elevation of the mold-frame and mold; and Fig. 6 is a plan of thelower half of the frame and a portion of the mold which is supportedand.

- operated thereon, a part of this mold being broken away to show moreclearly the mode of supporting and operating it from the moldframe. V InFig. 2 the mold is shown opened, so as to relieve the casting fromresistance during shrinkage after the metal is poured, and the wheel isshown as it"is after being bored,

turned, and finished, ready for placing upon its axle, to illustrate theclearance required; for shrinkage. In Fig. 4 the mold is shown: closed,ready to receive the molten metal. The space within the rim of the moldbeyond that required to contain the finished wheel indicates the amountof surplus metal provided as a' sinking head for supplying the shrinkagein the rim of the wheel, so that after this sink ing head is-cut off theremainder of this rinr will be solid. A sinking head is necessaryat 5'this place, because the plate between the rim and the hub is so thinthat it would chill solid before the rim had solidified. This chillingtbetween the rim and the hub would cut off any supply of metal from thesinking head atthe hub, and unless a supply from some other source isprovided the rim, when cold, would be hollow, because it solidifiesfirst upon the exterior, which defines the size, and the shri nkage incooling must be supplied'from the fluid? metal in the interior untilthis is exhausted. 1 Such a cavity would of itself weaken the rim fromthe absence of metal; but the metal immediately surrounding the cavitywould be weakened, owing to its irregular form and the l absence ofpressure in cooling. The certainty that such a cavity existed woulddetract from the value of the wheel; but the uncertainty as to itsextent would depreciate the market value still more.

The mold proper is composed of five principal parts. The rim A, Figs.2,4, and 5, which is supported by the lower frame, B, and in turnsupports the upper frame, 0, so that this rim is interposed between theupper and lower frame. They are all retained in position'laterally bythe small flanges a a on the rim A, and they are clamped togethervertically by the four hinged straps D D D D, which are attached,respectively, to the lower frame, B, by pin-joints. These straps swingover projections 00, cast upon the upper frame, so that as the strapsare pushed on these projections the upper and lower frame and the rim Aare wedged together. These projections also serve as handles by whichthe moldcan be stripped to remove the wheel after it is cast. The upperframe, 0, is provided with vertical bars a, by which the inner rim, E,is attached to the outer one, and this rim E is of such diam eter as toadmit the upper hub portion of the mold, F, and allow free playlaterally for the same. The hub Fis supported vertically only from therim E by means of the ring-plate b b and the standing bolts d d. Thelower hub portion of the mold, G, is supported upon the top of a similarrim, H, in the lower frame, and so as to have free play laterally. Theflanges at the upper andlower ends of the hubs G and F are circular andbeveled to admit the annular portions of the mold, J and K,

which, when closed, fill upthe space between the hub and the rim of themold.

The upper annulus of the mold, J, is supported from the upper frame, 0,at four points by thestrapsc c c c, which extend over cams formed intheshafts L L in the frame 0, as shown by dotted lines in Figs. 2 and 4.The bottoms of the openings in which these cams work areat suchadistance below the centers of the shafts "that the circular andouterportion of the cams will press on these bottoms when the annulus J isresting upon the rim A, so as to force theannulus against the rim, andwhen the shafts are turned so that the straps c a 0 0 are resting uponthe circular portion-of the cards the annulus J willibe raised,as shownin Fig. 2. The strapslc 0 0 a and the blocks with projecting arms M M,upon which they are supported, are securely attached to the annulus J bythe standing bolts 6 6 ea. The arms from these blocks project throughslots in the rim of the-frameO, forthe purpose hereinafter explained.

lnrorder that the shafts L *L 'may be rotated simultaneously andconveniently, a crank-arm, f, .is keyed upon the-endof one and ahandlever iupon the-other, and these two are connected by the illllk gg.

The lower annulus of the mold, K, is supported from the lower frame, B,at four points by the levers N N, the fulcrums of which are pins fixedin the frame. One end of each le Ila ver operates in a groove or slot ina projec' tion cast for the purpose on the under side of the annulus,and the outer end of each lever is provided with a swinging strut, m,which fits under the projecting arms from the blocks M M, so that theweight of the lower annulus, K, through the intervention of the levers NN, serves as a counter-balance to the upper annulus, J, and the two willopen and close simultaneously as the opening and closing devices (inthis instance the shafts L L and their cams) are rotated back and forth.

The annular portions of the mold, J and K, are provided with projectingflanges h h, overhanging the hub and rim of the mold, respectively,which act as squaring-pieces, to insure the accurate final closing ofthe mold.

It is evident that when. a wheel is to be cast with the plate, whichconnects the hub with the rim, entirely on one side of the rim, the hubportion of the mold on-that side may be a part of the frame, and themold would re quire only one rclieving-annulus. My improvements areequally applicable in such cases, the only modification requisite beingthat the single annulus must then be counterbalanced, if anycounterbalaneing is required, by a weight substituted for the omittedannulus.

In the center of the lower hub portion of the mold, G, I provide a blockof metal, 0, Fig.4, of suitable thickness to carry off the heat from thecast metal so rapidly that the metal will chill before it has time tosoften or to penetrate the side of the hub. The vertical position ofthis block in the mold determines the length of the lower hub of thewheelcasting, and this block is supported at the proper height by sandpacked in between it and the floor on which the mold rests. The upperhub portion of the mold is made of sufficient depth to contain thelength of the hub required on the wheel-casting, and a suitable lengthin addition for a sinking head.

The process of casting a wheel with the above-described mold is asfollows: The frame is to be placed substantially level, with the block 0supported at the proper height. The upper and lower frames must beclamped upon the rim of the mold by the four hinged straps D D, and thefour swinging struts on the end of the levers N N must be placed inposition under the projecting arms from the blocks M M. The annularportions of the mold must then be closed against the rim and hubportions by rotating the cam-shafts in the upper frame, which willadjust the hub portions of the mold radially-that is to say, to aposition concentric with the rim. The mold and frame thus closed andclamped is moderately heated before the cast is made, with a view toavoid a too sudden heating from the molten metal, and, when arranged asdescribed,

the metal is poured rapidly at the hub until the mold is full. The fitbetween the annular portion of the mold and the rim will ordinarily notbe so close as to prevent the escape of the air above the plate of thewheel; but to insure this escape with ease a few small grooves should befiled across these surfaces. After this cast has been made the mold isallowed to stand about one and a half minute, or until a skin of thecasting has set, when the leverhandle must be moved so as to open theannular portions of the mold and allow the necessary room for shrinkageof the wheel. When these portions of the mold have been removed, themetal in the casting will still be so supported by the lower hub and bythe bottom flange on the rim that the weight of the casting cannotdistort it. The length of time during which the annular portions of themold must remain closed after the cast has been made will vary somewhatwith the proportions of the wheel. It is only requisite to keep thoseportions of the mold closed until a skin is formed strong enough toprevent the fluid metal in the interior of the casting from bursting itwhen they are opened, and it is requisite that they should be openedbefore they can present any appreciable resistance to the shrinkage ofthe metal. As soon as the metal has solidified sufficiently to permitthe removal of the casting without distorting it, the swinging clampsand struts are thrown off,

and the upper rim,with the portions of the mold attached to it, arelifted off, and the casting can be lifted out of its place by the hub.The mold may then be reelosedas before, and the operation may berepeated as often as required. After the wheel has been removed from themold I prefer to pass it directly to the annealing-furnace, and after itis annealed the sinking heads of the hub and rim are out off and thewheel is bored and turned.

I have shown and described the rim of the mold, the supporting-frame,and the hub portions as separate and distinct from each other, becausewhen so constructed avariety of sizes of both rims and hub portionsmaybe used in the same supportingframcs. The several parts will then befree to expand with the heat of ICC the casting without one beingrestrained by the other, and those parts directly exposed to the moltenmetal can be rcplaced,when injured,with the least expense. But it isevident that in many cases the hub portion and the supporting-frame foreach half of the mold may be in one piece, the supporting-frame in thiscase being simply arms projecting from the hub portion to permit freeexpansion as the mold becomes heated, their outer ends beveled toreceive and center the rim, as shown in the drawings, of the outer edgeof the supportingframes. In such case the inner circumference of theannulus and the corresponding part of the hub portion must becylindrical in place of conical, as the annulus can only be then placedin position when the mold is open. The cylindrical joint between theannulus and the hub portion may be quite free without affording anyoutlet for the fluid metal, because it chills so rapidly that escapethrough a narrow aperture is impossible.

It is also evident that with such sizes or proportions of wheels thatwould not impart sufficient heat to the mold to make its expansion aserious element of destruction, the rim, hub portion, andsupporting-frame for each half of the mold may be in one piece; or thewhole rim and the supporting-frame and hub portion for one half of themold may be in one piece, and the supporting-frame and the hubstruction; but in all such cases the removable piece could be takencompletely away from the mold, leaving the mold as a whole connected'and self-supporting; but in casting a.

wheel in which the rim is connected with the hub by arms or by a plateor web that is narrower than the rim to which my improvements areadapted it is requisite to remove an annular portion of the mold betweenthe rim and the hub to permit unobstructed shrinkage of the casting, andthis must necessarily cut off the rim from the hub portion. With a moldhaving its central part entirely separated from and unsupported by theouter portions provision must be made for maintaining the several partsin proper relation to each other, so that when closed the matrix shallbe perfect and continuous, to prevent the escape of the fluid metal whenpoured into it, and this I accomplish by the mold-frame, in which thedevices for opening and closing the annular portions are placed, ashereinbefore described 5 and whether this mold-frame is in one piecewith the hub portion or with the rim and the hub portions, or inseparate pieces, as shown and described, the annular movable portionsmust of necessity remain within the mold or its supporting-frame. In allmolds heretofore employed for relieving strains in castings portions ofthe upper half alone have been removable, and the cast metal has beensupported over its whole under surface by the mold after the removal ofthe relieving portions. No mold has heretofore been employed in whichany portion of the under or lower side of the cast metal could be leftentirely without support immediately af-' ter casting; no mold hasheretofore been employed in which any portion of both the upper andlower halves were removable, so as to leave the cast metal unsupportedon. both sides when the relieving portions of the mold have withdrawntheir support before the cast metal has contracted appreciably; no moldhas heretofore been employed in which a movable relieving portion of itmust of necessity remain within the mold or its supporting- .frame, andno mold has heretofore been employed in which two or more relievingportions counterbalance each other. All of these features are necessaryto successfully cast such wheels as I propose to make, and all of thesefeatures are prominent in my mold, and these characteristics clearlydistinguish it from all other relieving and supporting molds.

Having thus described the natureand object of my invention, what I claimas new, and desire to secure by Letters Patent, is-

1. In a metal mold for casting steel wheels, a rim, a supporting-frameby which a hub portion of the mold. is supported, and a movablerelieving-annulus between the rim and the hub portion, substantially asand for the purposes set forth.

2. In a metal mold for casting steel wheels, a rim and supporting-frameswhich maintain the hub portions of the mold at the proper distance fromeach other, in combination with a movable annulus which determines theposition of its hub portion radially, substantially as described.

3. In a metal mold for casting steel wheels, an upper movable annulusand a lower movable annulus between the rim and the hub portions of themold, substantially asand for the purposes set forth.

4. In a metal mold for casting steel wheels,

an upper and a lower movable annulus, in combination with devicesthrough which one annulus is made to counterbalance the other,substantially as described.

5. A metal mold for casting steel wheels, provided with space for asinking head within the rim portion of the mold and above the true rimof the finished wheel, substantially as described.

WM. SELLERS. Witnesses:

CHAS. M. MILLER, DAVID L. LUKENS.

